1. Technical Field
The present disclosure relates to an electrosurgical instrument and method for sealing tissue. More particularly, the present disclosure relates to an electrosurgical tool including opposing jaw members having sealing plates with improved non-stick coatings and methods for manufacturing the same.
2. Background of the Related Art
Electrosurgical forceps utilize mechanical clamping action along with electrical energy to effect hemostasis on the clamped tissue. The forceps (open, laparoscopic or endoscopic) include electrosurgical sealing plates which apply the electrosurgical energy to the clamped tissue. By controlling the intensity, frequency and duration of the electrosurgical energy applied through the sealing plates to the tissue, the surgeon can coagulate, cauterize, and/or seal tissue.
During an electrosurgical procedure, tissue sealing plates are used to apply electrosurgical energy to tissue. Because the sealing plates conduct electricity, care must be taken to electrically insulate the sealing plates from other electrically conductive components of the electrosurgical forceps and to limit and/or reduce many of the known undesirable effects related to tissue sealing, e.g., flashover, thermal spread, and stray current dissipation. Typically, tissue sealing surfaces are disposed on inner facing surfaces of opposing jaw members such that the tissue sealing surfaces are utilized to seal tissue grasped between the jaw members. Often, the manufacturing of jaw members requires the use of a two-shot molding process that includes a pre-shot overmold of insulative material (e.g., plastic) placed between the underside of the sealing plate and the steel structural support base of the jaw member to provide electrical insulation between the jaw member and the tissue sealing surface.
In the past, significant efforts have been directed to improvements in electrosurgical instruments and the like, with a view towards providing improved transmission of electrical energy to patient tissue in both an effective manner and to reduce the sticking of soft tissue to the instrument's surface during application. In general, such efforts have envisioned non-stick surface coatings, such as polymeric materials, e.g. polytetrafluoroethylene (PTFE, commonly sold under the trademark TEFLON®) for increasing the lubricity of the tool surface. However, these materials may interfere with the efficacy and efficiency of hemostasis and have a tendency to release from the instrument's substrate due to formation of microporosity, delamination, and/or abrasive wear, thus exposing underlying portions of the instrument to direct tissue contact and related sticking issues. In turn, these holes or voids in the coating lead to nonuniform variations in the capacitive transmission of the electrical energy to the tissue of the patient and may create localized excess heating, resulting in tissue damage, undesired irregular sticking of tissue to the electrodes and further degradation of the non-stick coating.